Apparatus and method for authoring and maintaining a library of content and targeting content to a playback device

ABSTRACT

A computer network based digital information library system employing authentication and encryption protocols for the secure transfer of digital information library programs to a client computer system and a mobile digital information playback device removably connectable to the client computer system. The present invention is a computer network based library and information delivery system for accessing and obtaining selected digital information files. The library and information delivery system comprises: 1) a library server having a plurality of digital information files; 2) a client computer system coupled to the library server over a network; and 3) a mobile device removably connectable to the client computer system, the client computer system including logic for requesting a download of a selected one or more of the digital information files from the library server, the client computer system further including logic for downloading the selected one or more of the digital information files to the mobile device.

The present patent application is a divisional of Ser. No. 09/234,044filed Jan. 19, 1999, which is a continuation of Ser. No. 08/710,114filed Sep. 12, 1996 now issued as U.S. Pat. No. 5,926,624.

FIELD OF THE INVENTION

The present invention relates generally to a digital informationtransmission, receiving, and playback system. Specifically, the presentinvention pertains to a computer network based digital informationlibrary providing interactive client computer access.

DESCRIPTION OF RELATED ART

Recent technological advances in the compression of digital data and theexpansion of storage capacities of computer systems together with theincreased bandwidth of computer network infrastructures have created newpossibilities for personalized access to and usage of large amounts ofdigital information. One form of this type of digital information isaudio information delivered across a computer network as digitizedinformation.

In the field of interactive digital information transmission, receiving,and playback systems, several patents are known to the presentapplicants. U.S. Pat. No. 5,132,992, issued Jul. 21, 1992 to Yurt et al.(Yurt), describes a system of distributing video and/or audioinformation employing digital signal processing to achieve high rates ofdata compression. The Yurt patent describes a transmission systemincluding a conversion means for placing the items from a sourcematerial library into a predetermined format as formatted data. Audiodata is compressed by an audio compressor by application of an adaptivedifferential pulse code modulation (ADPCM) process to the audio data.Stored items are accessed in the compressed data library through the useof a unique address code assigned to each item during storage encoding.The unique address code is used for requesting and accessing informationand items throughout the Yurt transmission and receiving process. TheYurt transmission system includes means by which a user enters acustomer identifier (ID) code by which the system accesses the usersaccount, and indicates to the system that the user is a subscriber ofthe system. If a subscriber is in good standing, the Yurt systemdelivers selected titles using the described techniques.

One significant problem with the audio transmission and receiving systemdescribed in Yurt is the lack of an effective means for ensuring thesecurity of the digital information library and of the items downloadedto a user from the digital information library. Although Yurt describesthe use of a unique identification code assigned to items in the libraryand a customer ID code assigned to particular users, no authenticationprotocols or encryption techniques are described to prevent theunauthorized creation of clone libraries or the unauthorized download orcopying of library items. Secondly, Yurt and related prior art does notdescribe an authentication or encryption means providing securetransactions between a server based digital information librarysupporting a client computer system having an interface to a mobileplayback device. Thirdly, the prior art does not describe a mechanismfor selecting a digital information passage to be previewed. Prior artsystems also do not describe a system whereby only part of a programgets downloaded from a client computer system to a mobile playbackdevice depending on how much storage space is available in the mobileplayback device. Prior art systems also do not describe a mechanism forspecifying multiple programs to be downloaded from a digital informationlibrary into a mobile playback device. Prior art systems also do notdetail the processes required in the authoring system to generatecontent for the digital information library. Finally, prior art systemsdo not describe an accounting system whereby library content providerscan perform real-time queries on usage information related to the accessof library items.

SUMMARY OF THE INVENTION

The preferred embodiment of the present invention is a computer networkbased digital information library system employing authentication,targeting, and encryption protocols for the secure transfer of digitalinformation library programs to a client computer system and a mobiledigital information playback device removably connectable to the clientcomputer system. The present invention is a computer network basedlibrary and information delivery system for accessing and obtainingselected digital information files. The library and information deliverysystem comprises: 1) a library server having a plurality of digitalinformation files; 2) a client computer system coupled to the libraryserver over a network; and 3) a mobile device removably connectable tothe client computer system, the client computer system including logicfor requesting a download of a selected one or more of the digitalinformation files from the library server, the client computer systemfurther including logic for downloading the selected one or more of thedigital information files to the mobile device.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included as part of the presentspecification, illustrate the presently preferred embodiment of thepresent invention and together with the general description given aboveand the detailed description of the preferred embodiment given belowserve to explain and teach the principles of the present invention.

FIG. 1 illustrates a typical computer platform on which the presentinvention may be implemented.

FIG. 2 illustrates a high level block diagram of the computer networkbased digital information library system of the present invention.

FIG. 3 illustrates a high level block diagram of the authoring system ofthe present invention.

FIG. 4 illustrates an alternative embodiment having a plurality oflibrary servers.

FIG. 5 illustrates an alternative embodiment having a plurality oflibrary server processes.

FIG. 6 illustrates an alternative embodiment having a singleauthoring/authorization server.

FIG. 7 illustrates an alternative embodiment wherein client computersystems have a local library.

FIG. 8 illustrates an alternative embodiment wherein mobile playbackdevices have a direct network interface in lieu of a client computersystem.

FIG. 9 illustrates an alternative embodiment wherein a kiosk is used toretain and distribute selected programming.

FIG. 10 illustrates an alternative embodiment wherein all systemcomponents are connected through a common network.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The preferred embodiment of the present invention is a computer networkbased digital information library system employing authentication,targeting, and encryption protocols for the secure transfer of digitalinformation library programs to a client computer system and a mobiledigital information playback device removably connectable to the clientcomputer system. In the following detailed description, numerousspecific details are set forth in order to provide a thoroughunderstanding of the present invention. However, it will be apparent toone of ordinary skill in the art that these specific details need not beused to practice the present invention. In other instances, well knownstructures, interfaces, and processes have not been shown in detail inorder not to unnecessarily obscure the present invention.

FIG. 1 illustrates a typical data processing system upon which oneembodiment of the present invention is implemented. It will be apparentto those of ordinary skill in the art, however that other alternativesystems of various system architectures may also be used. The dataprocessing system illustrated in FIG. 1 includes a bus or other internalcommunication means 101 for communicating information, and a processor102 coupled to the bus 101 for processing information. The systemfurther comprises a random access memory (RAM) or other volatile storagedevice 104 (referred to as main memory), coupled to bus 101 for storinginformation and instructions to be executed by processor 102. Mainmemory 104 also may be used for storing temporary variables or otherintermediate information during execution of instructions by processor102. The system also comprises a read only memory (ROM) and/or staticstorage device 106 coupled to bus 101 for storing static information andinstructions for processor 102, and a mass storage device 107 such as amagnetic disk drive or optical disk drive. Mass storage device 107 iscoupled to bus 101 and is typically used with a computer readable massstorage medium 108, such as a magnetic or optical disk, for storage ofinformation and instructions. The system may further be coupled to adisplay device 121, such as a cathode ray tube (CRT) or a liquid crystaldisplay (LCD) coupled to bus 101 through bus 103 for displayinginformation to a computer user. An alphanumeric input device 122,including alphanumeric and other keys, may also be coupled to bus 101through bus 103 for communicating information and command selections toprocessor 102. An additional user input device is cursor control 123,such as a mouse, a trackball, stylus, or cursor direction keys coupledto bus 101 through bus 103 for communicating direction information andcommand selections to processor 102, and for controlling cursor movementon display device 121. Another device which may optionally be coupled tobus 101 through bus 103 is a hard copy device 124 which may be used forprinting instructions, data, or other information on a medium such aspaper, film, or similar types of media. In the preferred embodiment, acommunication device 125 is coupled to bus 101 through bus 103 for usein accessing other nodes of a network computer system or other computerperipherals. This communication device 125 may include any of a numberof commercially available networking peripheral devices such as thoseused for coupling to an Ethernet, token ring, Internet, or wide areanetwork. It may also include any number of commercially availableperipheral devices designed to communicate with remote computerperipherals such as scanners, terminals, specialized printers, or audioinput/output devices. Communication device 125 may also include an RS232or other conventional serial port, a conventional parallel port, a smallcomputer system interface (SCSI) port or other data communication means.Communications device 125 may use a wireless means of data transferdevices such as the infrared IRDA protocol, spread-spectrum, or wirelessLAN. In addition, communication device 125 is used in the preferredembodiment to couple the mobile playback device 212 to the clientcomputer system 214 as described in more detail below. One other deviceused in the preferred embodiment is sound circuitry 130 either withattached speakers or headphones 132, or with analog audio outputssuitable for input into audio reproduction equipment such as externalamplifiers and speakers, cassette adapters, etc. Sound circuitry 130 iswell known in the art for playing audio files. Alternatively, soundcircuitry may be a radio transmitter which transmits audio data on apredefined frequency for reception and playback by a radio receiver.Other wireless methods are possible.

Note that any or all of the components of the system illustrated in FIG.1 and associated hardware may be used in various embodiments of thepresent invention; however, it will be appreciated by those of ordinaryskill in the art that any configuration of the system may be used forvarious purposes according to the particular implementation. In oneembodiment of the present invention, the data processing systemillustrated in FIG. 1 is an IBM® compatible personal computer (PC), anApple MacIntosh® personal computer, or a SUN® SPARC Workstation.Processor 102 may be one of the 80X86 compatible microprocessors such asthe 80486 or PENTIUM® brand microprocessors manufactured by INTEL®Corporation of Santa Clara, Calif.

The software implementing the present invention can be stored in mainmemory 104, mass storage device 107, Or other storage medium accessibleto processor 102. It will be apparent to those of ordinary skill in theart that the methods and processes described herein can be implementedas software stored in main memory 104 or read only memory 106 andexecuted by processor 102. This software may also be resident on anarticle of manufacture comprising a computer usable mass storage medium108 having computer readable program code embodied therein and beingreadable by the mass storage device 107 and for causing the processor102 to perform digital information library transactions and protocols inaccordance with the teachings herein.

Digital Information Library System

FIG. 2 illustrates the computer network architecture used in thepreferred embodiment of the present invention. In general, the networkarchitecture of the present invention includes a library site 250coupled to a client site 210 via a conventional distribution networkinfrastructure 240. This conventional distribution networkinfrastructure 240 can be implemented as a standard telephone connectionprovided between the library site 250 and client site 210 through anInternet provider to enable data communication on the Internet over aconventional telephone network. This use of the Internet as adistribution network is well known to those of ordinary skill in theart. In an alternative embodiment having cable modem capability,communication over a conventional cable network is possible in lieu ofcommunication over the telephone network. The cable network is typicallymuch faster (i.e. provides a much greater bandwidth) than the standardtelephone network; however, cable modems are typically more expensivethan standard POTS (plain old telephone system) modems. In anotheralternative embodiment having conventional Integrated Services DigitalNetwork (ISDN) capability, the distribution network 240 is accessedusing an ISDN modem. Again, the ISDN network is typically faster thanthe POTS network; however, access to an ISDN network is generally moreexpensive. Cable modems and ISDN implementations are alternativecommunications media to the POTS implementation.

In addition, it will be apparent to those of ordinary skill in the artthat other forms of networking may equivalently be supported by thepresent invention. For example, a wireless transmission means such asinfrared or radio links may also provide the distribution network 240described in the present application. As an alternative to the Internet,a proprietary network/bulletin board such as AMERICA-ON-LINE (AOL), orCOMPUSERVE may be used.

Each of the servers at library site 250 and the client computer system214 at client site 210 can be implemented as a computer system such asthe one described above in connection with FIG. 1. It will be apparentto one of ordinary skill in the art that the library server 260,authoring system 280, and authorization server 270 can be remotelylocated yet networked together as a distributed system using thetechniques described above. In addition, the present invention allowsfor multiple library servers, authoring systems and authorizationservers. Conversely, the servers may be implemented as separatefunctions of a single machine. These alternative embodiments areillustrated in FIGS. 4-8 and are described in more detail below.

The mobile playback device 212 is a minimally configured, low-cost,standalone mobile unit for receiving and storing digital informationfiles or programs as downloaded by library server 260 and clientcomputer system 214 and for playing back the digital information filesor programs for a user of the mobile playback device 212. The mobileplayback device 212 is temporarily removably coupled to the clientcomputer system 214 while the download takes place. Once downloaded, themobile playback device 212 may be detached from the client computersystem 214 and used as a standalone digital information playback device.A co-pending U.S. Patent Application titled, “Interactive AudioTransmission, Receiving and Playback System”, assigned Ser. No.08/490,537, and assigned to the Audible Words Corporation of Montclair,N.J. describes the details of mobile playback device 212.

In its basic form, the preferred embodiment of the present invention isa digital information library system providing selection of digitalinformation programming on demand over a computer network. In analternative embodiment, the digital information programming is selectedvia the computer network but delivered using mass storage media 241.This alternative embodiment is described in more detail below.

The digital information library is an indexed collection of digitalinformation programming, drawing content from digital informationsources such as books, daily news and entertainment feeds, conferencesand educational sources, other computer systems, the host on the WorldWide Web (WWW) of the Internet, and customized audio or visual imageprogramming. Other sources of the digital information content include,but are not limited to, conference or seminar proceedings, lecture orspeech materials, language lessons, readings, comedy, customized spokendigests and related, “need-to-know” business information, computersoftware, local sound studio material, text to speech conversion ofmachine readable files, pre-recorded material from magnetic tape,CD-ROM, digital audio tape, or analog cassette tape. This digitalinformation content is input as raw digital information content toauthoring system 280 shown in FIG. 2. In an alternative embodiment, araw digital information digitizer 307 is included for receiving rawinput and converting the input to a digital form which can bemanipulated as a digital information file.

In an alternative embodiment, the digital information comprisesdigitized image or graphics data used to produce visual images on adisplay screen or projection screen. These images may be included in thedigital information retained and maintained by the library server 260.

Authoring System

Authoring system 280 is used to edit, index, compress, scramble,segment, and catalog digital information content into digitalinformation programs in digital information files, which are stored onmass storage media 241 or on library server 260 as scrambled andcompressed digital information files 262. The digital informationprograms are initially categorized according to traditional criteria(e.g. genre, modern fiction, mystery, adventure, romance, non-fiction,classics, self-help, science fiction, westerns, etc.). Categoriesassociated with specific authors or publishers are also provided. Bothunabridged and abridged titles are provided. In some circumstances, itmay be necessary to digitize digital information content from anundigitized form. The raw information digitizer 307 is provided for thispurpose. Authoring system 280 also partitions digital informationcontent into segments, which can be identified, searched, and skippedover if desired. All of these functions are performed by authoringsystem 280.

FIG. 3 illustrates the authoring system 280 of the preferred embodiment.Authoring system 280 receives digital information content from a varietyof conventional sources as raw digitized data. This digital informationdata is fed to three components of the authoring system 280 of thepreferred embodiment. The digital information compressor 314 receivesthe raw digital data and compresses the digitized data. There are avariety of conventional techniques in existence for compressing digitaldata. These techniques can be optimized depending upon the type ofdigital data being processed. Thus, the present invention providesseveral compression methods and a means for the authoring systemoperator 305 to select between these methods based upon the category ofdigital information content 310 being input to the digital informationcompressor 314. Alternatively, the selection of compression method maybe performed automatically by interpretation of the digital informationcontent 310 itself. A compressed digital information file is output bydigital information compressor 314 to scrambler 318.

The raw digital information content 310 is also fed to template headergenerator 312. Each digital information file maintained by the libraryserver 260 includes other descriptive information used to identify thefile's content and to provide information used to process the digitalinformation within the file. Each digital information file includes atemplate header, a descrambling map, selected preview clips, and thedigital information programming itself. In the preferred embodiment, thetemplate header comprises a number of attributes corresponding to thedigital information in the file. For example, the digital informationmay be audio information generated from the content of a book or otherpublished work. In this example, the audio file template header containsattributes including: 1) the title of a book, volume, or medium fromwhich the digital information content originated, 2) the legal copyrightassociated with the digital information content, 3) audible title(s) ofthe content, 4) a table of contents of the content, and 5) playbacksettings for appropriately playing or rendering the digital information.The table of contents contains content navigation information includingbut not limited to: the number of chapters, the length of the program,and information indicative of the relevant content sections. The tableof contents is generated with input from authoring system operator 305or automatically by analysis of digital information content 310. Thedescrambling map 322 is used to interpret the digital information afterthe digital information has been scrambled by scrambler 318 as describedbelow. The preview clips 324 comprise short pre-generated portions ofdigital information content used to give a consumer a sense of thecontent of a particular digital information file. In the preferredembodiment, these previews are generated as conventional formatted fileswhich can be directly played by sound generation circuitry 130 orrendered by other means. A digital information file can have severalpreview clips associated with it. The preview clips 324 are notcompressed or scrambled in the preferred embodiment. The template header312 remains with the digital information file as it is transferred tothe network 240 or mass storage media 241. The other descriptiveinformation related to a digital information file is typically storedwith digital information file, but is not required to be so stored.

Referring again to FIG. 3, template header generator 312 generates thetemplate header given information from a particular portion of digitalinformation content 310. Input from Authoring System Operator 305 andDigital Information Compressor 314 may be solicited during the headergeneration process. The template header is provided to library server260. Other portions of the digital information file header are providedby scrambler 318 and preview generator 323. These portions of thedigital information file header are assembled into the header for aparticular digital information file by library server 260. The remainderof the digital information file is filled with compressed, scrambled,and segmented digital information content.

After digital information compressor 314 has compressed the raw digitalinformation using a selected compression method suitable for thecategory of digital information, the scrambler 318 scrambles the digitalinformation. The digital information is scrambled to prevent anunauthorized consumer from using the digital information. In thepreferred embodiment, scrambler 318 uses a conventional encryptionmethod to render the data unusable. A corresponding descrambling map 322is generated to provide a means for descrambling the scrambled digitalinformation file. A scrambling map 316 is used by scrambler 318 toscramble the digital information file. The scrambler 318 can encrypt theentire digital information file or selected critical subsets of thedigital information file. The level of scrambling can be selecteddepending upon the capabilities of the authoring system 280, the mobileplayback device 212 and/or the anticipated software player 226 on clientcomputer system 214. In an alternative embodiment, a proprietary digitalinformation format is used in lieu of scrambler 318.

The scrambled digital information content is output by scrambler 318 tosegmentation logic 326. Segmentation logic 326 petitions the digitalinformation content into blocks for efficient storage in and transfer toa mobile playback device 212 or software player 226 and for efficientnavigation during playback. Transport integrity data is generated andappended to the segmented digital information. In an alternateembodiment, portions of the segmentation process may take place beforeor after digital information compressor 314 and scrambler 318.Segmentation information may also be used in the header generationprocess by template header generator 312. The compressed, scrambled, andsegmented digital information blocks are provided to the library server260 by authoring system 280. Library server 260 assembles the segmenteddigital information blocks, the descrambling map 322, the previewclip(s) 324, and the template header 312 for a particular item ofdigital information content into a digital information program file orfiles, which are stored in a digital information program file storagearea 262. Other raw digital information content is converted intodigital information files using the authoring system 280 in a similarmanner.

Library Server

Referring again to FIG. 2, the library server 260 is responsible formaintaining the digital information program files 262 created by theauthoring system 280. In addition, the library server 260 receivesrequests for access to the digital information program files 262 fromclient computer systems 214 over network 240 and manages purchase anddelivery of the selected digital information files and/or delivery ofselected preview clips 324. The library server 260 includes librarymanagement software 261 for performing these library server functionsand a library key 263 used for the authentication protocol describedbelow. Library management software 261 includes processing logic forreceiving and responding to client computer system 214 requests foraccess and/or purchase of a digital information program file 262. Uponreceiving such a client request, library server 260 uses authorizationserver 270 to authenticate the request with client information 272generated and maintained by library server 260 or authorization server270. The client information 272 includes client identifiers which areused to target content for playback on individual mobile playbackdevices 212 or software players 226. Client information 272 may alsocontain client personal information, user content preferences, clientbilling history, player usage history, and player group lists. In analternative embodiment, portions of client information 272 may insteadbe stored in server 260. Using the authorization protocol described inmore detail below, the library server 260 determines if the clientrequest can be serviced. If approved, the library server 260 accessesthe digital information program file(s) or preview clip(s) requested bythe client computer system 214, delivers the selected preview clip(s) orbuilds encrypted, targeted, and digitally signed digital informationfiles using the authentication protocol described in more detail below,and transfers the encrypted and compressed digital information file(s)to the requesting client computer system 214 via network 240.Distributable mass storage media 241 may also be used as a deliverymedium for the transfer of information to client system 214. The clientcomputer system 214 may then independently download the selected digitalinformation files (or a subset thereof) into the mobile playback device212 for subsequent playback. The library server 260 also collects usagestatistics on the access history of the digital information files 262and stores this usage data into usage statistic storage area 264. Thelibrary server 260 also stores operating code segments (firmware) forthe client browser 219, software player 226, and for mobile playbackdevice 212. This operating code can be downloaded to the client computersystem 214 in the same manner as digital information files aretransferred. Player configuration data for playback device 212 andsoftware player 226 is stored on the library server 260 and can becustomized or updated in the same manner as digital information filesand firmware are transferred. Configuration data includes, but is notlimited to, audio prompts, user interface options, group ID information,and information playback parameters. Player configuration data istransferred to client computer system 214, software player 226, ormobile playback device 212 as required according to client information272.

The library server 260 interfaces with a client application program orclient browser 219 executing on client computer system 214. The clientbrowser 219 is used to make requests of library server 260 for varioustypes of service including, but not limited to, searching the digitalinformation files 262 for a desired program, previewing a selectedpreview clip associated with a digital information file 262, purchasinga selected program, requesting operating code segments or playerconfiguration data, and downloading the purchased program or othermaterial to the requesting client computer system 214.

The library server 260 interface with the authorization server 270 andclient computer system 214 uses the unique authentication protocol andencryption protocol of the preferred embodiment of the presentinvention. The preferred embodiment of these protocols is described inthe sections below.

Client Computer System

Referring again to FIG. 2, the client computer system 214 represents aconsumer or end user computer system, typically a personal computer,such as the sample system illustrated in FIG. 1, with which a consumermay browse, preview, select, purchase, and take delivery of digitalinformation content from digital information library server 260 acrossdistribution network 240. Client computer system 214 comprises clientbrowser software 219, a mobile device interface 221, storage forencrypted and compressed digital information files 220 downloaded fromthe network 240, software player 226, and segment download data 222derived from digital information files 220 for defining the storagesegments in mobile playback device 212 and for assisting in thedownloading of digital information files 220 from client computer system214 to mobile playback device 212. Client computer system 214 alsoincludes a server public key 215 used for authenticating digitalinformation and software files received from server 260. Client browsersoftware 219 provides the control logic with which the client orconsumer accesses and purchases titles from the digital informationlibrary 262 of library server 260. Client browser software 219 alsoprovides control logic which requests and downloads configurationinformation or operating code from server 260. The client browsersoftware 219 can be configured to perform these operations withoutdirect human intervention. The mobile device interface 221 is a softwareinterface used to control the transfer of control information, operatingcode, and digital information files from client computer system 214 tomobile playback device 212. Encrypted and compressed digital informationfiles 220 are received by client computer system 214 from library server260 over network 240. In an alternate embodiment, distributable massstorage media 241 is used instead of network 240 to transfer informationto client computer system 214. The software player 226 is a softwaremodule used to emulate the operation of mobile playback device 212 andfor playing digital information files through the sound circuitry 130and audio output device 132 of client computer system 214. Operatingcode and configuration information for the software player 226 can bedownloaded or updated from the server 260 in the same manner as themobile playback device 212 can be downloaded or updated. The softwareplayer 226 functionality is the equivalent of the functionality andoperation of the mobile playback device 212. Thus, the use of the term“player” throughout this document generally applies to both the mobileplayback device 212 and software player 226. Software players 226 areassigned unique player IDs and can be assigned group IDs that functionsimilarly to IDs assigned to mobile playback devices 212.

Mobile Playback Device

The mobile playback device 212 converts a digital information file intosound or displayable imagery which is played through audio output meansor displayed on a display device. In the preferred embodiment, themobile playback device 212 is a minimal capability, low-cost deviceprimarily dedicated to playing audio files or displaying visual imagesor text on a display device. The mobile playback device 212 is minimallyconfigured to retain its light-weight, low cost, and readily mobilefeatures. The preferred embodiment does not therefore include the use ofa portable personal computer or laptop computer as the mobile playbackdevice 212; because, such general purpose computing devices typically donot meet the light-weight and low cost constraints of the preferredmobile playback device 212. Such general purpose computing devicestypically have unnecessary functionality, more complicated interfaces,and may suffer cost and performance penalties in comparison to thespecial purpose mobile playback device 212. In the preferred embodiment,the mobile playback device 212 includes a processor, memory, and aninterface to client computer system 214 over which compressed digitalinformation files 216 are received. As described in more detail below,mobile playback device 212 also includes a player ID 223, group IDs 225,and server public key 215 used for authenticating digital informationand software files received from server 260 via client computer system214. The user controls the mobile playback device 212 using buttons andknobs provided on the device. These controls are used to navigatethrough digital information files 216, adjust configuration data andplayback parameters, or perform other functions as directed by firmwarestored in playback device 212. When coupled to the player, clientcomputer system 214 or other electronic devices can solicit user inputfrom these controls. In an alternative embodiment, a set of additionaluser controls is provided on a remote control unit that is coupled tothe player via a wired or wireless connection. Digital informationoutput may be provided via a headphone jack, on board speaker, orwireless transmitter to a separate wireless receiver with speakers orheadphones. Audio level can be adjusted with a volume knob. A wirelesstransmitter may contain an adjustment knob to adjust the transmissionfrequency or other transmission parameters. Visual information output isprovided via LCD display, LED display, or outputs to a standard visualdisplay device. The mobile playback device 212 contains a limitedquantity of non-volatile memory, RAM, and ROM. Digital informationcontent, configuration data, and operating code are stored in the memoryspace of the mobile playback device 212. Configuration data includes butis not limited to: public and private IDs, content playback parameters,and user interface parameters. The use of non-volatile memory allowsportions of the digital information content, configuration data, andfirmware to be updated via download. Both digital information contentand firmware (operating software) is stored in this memory device.Portions of the firmware and configuration information are storedpermanently in a read only memory (ROM). An internal memory allocationmethod is used to track the content of mobile playback device 212memory. This allocation method, in conjunction with segment navigationdata 218, also provides the means for locating desired digitalinformation, program, configuration data, or header data resident in themobile playback device 212 memory. The mobile playback device 212includes an interface to the client computer system 214 through whichthe mobile playback device 212 receives compressed digital informationfiles 216, software updates, and configuration changes from clientcomputer system 214.

Downloading Digital Information Content, Software Updates, orConfiguration Information From the Library Server to the Client ComputerSystem

The client browser software 219 of client computer system 214 operatesin cooperation with library management software 261 of library server260 and the firmware resident on the mobile playback device 212 toprovide a means by which a consumer may browse, preview, select,purchase, and take delivery of selected digital information content fromdigital information library server 260 across distribution network 240.The digital information content is typically downloaded to the clientcomputer system 214 at the time of purchase, but it is possible todownload digital information content either, 1) sometime after thepurchase, or 2) multiple times after an initial purchase. The clientbrowser 219 can be configured to download content to client computersystem 214 without user intervention. In addition, portions of theclient computer system 214 software itself or mobile playback device 212resident software/firmware may be downloaded or updated from libraryserver 260. The mobile playback device 212 resident software/firmware isdownloaded through client computer system 214. If library server 260 hasan updated or more recent copy of client computer system 214 software ormobile playback device 212 software/firmware, the library server copy isdownloaded to replace the outdated version of the corresponding clientcomputer system 214 software or mobile playback device software 212. Thesoftware is encrypted, scrambled, and digitally signed in a mannersimilar to the scrambling and delivery of the digital information files.Changes to the ID list, audio prompts, and other configuration data forplayback device 212 can be downloaded in a manner similar to thedownloading of software updates from library server 260.

The preferred embodiment utilizes three authentication processes toprotect the transfer of information from server 260 to client system 214and playback device 212. First, a point-to-point authentication protocolis performed whereby the library server 260 must verify that therequesting client computer system 214 is an authorized client and theclient computer system 214 must verify that the library server 260 is anauthorized provider. Secondly, a targeting protocol is performed wherebythe library server 260 utilizes a set of identifiers (i.e. player IDs)for mobile playback devices 212 authorized to receive the selecteddownload data from library server 260. The mobile playback deviceidentifiers are provided by client computer system 214 or are referencedfrom user profiles stored on library server 260. In the targetingprocess, library server 260 formats and downloads data that can only beread by mobile devices 212 with these identifiers. Thirdly, a libraryserver digital signature is appended to the downloaded data for use bythe mobile playback device 212 to verify that the downloaded data wasoriginated by an authorized library server. These three authenticationprocesses of the present invention are described in detail in thefollowing sections.

Point-to-Point Authentication Protocol

The library server 260, client computer system 214, and mobile playbackdevices 212 each have a unique verification sequence which is used toverify the authenticity of another system. In communications betweenlibrary server 260 and client system 214, both systems alternately actto (1) request verification of the other system and (2) provide anauthenticating response to a verification request. Communication betweenmobile devices 212 and client computer system 214 use a similarauthentication protocol, as well as real-time communication betweenmobile devices 212 and library server 260 via client system 214. Thisverification sequence comprises a pre-defined set of bit streams or datastructures which are sent by the requesting system (i.e. the systemrequesting verification) to the receiving system being authenticated(i.e. the respondent) in a point-to-point transmission. The receivingsystem must respond to the verification sequence in a pre-defined mannerby sending particular response bit streams or data structures to therequesting system. If the appropriate response data from the respondentis received by the requesting system, the system being verified isconsidered an authorized system. Conversely, the system being verifiedis considered unauthorized if the appropriate response data is notreceived by the requesting system prior to a pre-defined time-outperiod. Both systems begin communication by acting as requesters andrespondents in separate verification cycles. Upon completion of thesepoint-to-point authentication cycles, further client/server processingonly continues if both systems deem each other to be authorized systems.

In an alternate embodiment, point-to-point authentication is used in asubset of the communications among library server 260, client computersystem 214, and mobile playback devices 212. In another embodiment,point-to-point authentication is not used and system security rests onthe use of targeting and/or digital signature authentication.

Targeting Protocol

The targeting protocol of the present invention is a means and methodfor limiting the playback of digital information content, the adjustmentof player configuration data, and the download of player operating codeto a specified player 212/226 or a specified set of mobile playbackdevices 212. Each player 212/226 contains a unique player ID 223. Theplayer ID 223 comprises a public player ID and a private player ID. Thepublic player ID is a unique identifier and serves as a serial numberfor player identification. The private player ID is used to target datafor individual mobile playback devices 212. Private player IDs are neversent through any communications link or network path, except duringinstallation. In the preferred embodiment, private player IDs should besufficiently diverse, but need not be unique.

Mobile playback devices 212 may be logically grouped together using aGroup ID. Digital information content, software, or configuration datachanges may be targeted to a group of mobile playback devices 212defined by a group ID. Each player 212/226 includes memory space forstorage of one or more group IDs 225 of which the particular player212/226 is a member. Each group ID includes a public portion and aprivate portion, each of which is equivalent to the public and privateplayer IDs, respectively. Each group is identified by a uniquely valuedpublic ID that is not shared with other player or group IDs. Digitalinformation content, software, or configuration data can be targeted toa particular group ID in the same way as it would be targeted for aspecific player ID. Mobile playback devices 212 in the same group sharethe same Group ID. A particular Group ID is pre-defined as the globalgroup to which all mobile playback devices 212 are a member. Mobileplayback devices 212 may be members of more than one group. A particularplayer 212/226 is added to a new group by appending the new group ID tothe set of group IDs 225 maintained in the particular player 212/226.The new group ID is appended after the server 260 provides a publicgroup ID and a group key to the player 212/226 via client computersystem 214. The player 212/226 generates a private group ID from thecombination of the group key and the mobile playback device's 212private player ID. As with the private player ID, the private group IDis never sent through any communications link or network path, exceptduring installation. In an alternative embodiment, players receive thegroup private ID directly or by combining the group key with the playerspublic ID or other known numeric value. In another alternativeembodiment, the private group ID is not used in the targeting processand is not transferred to the player. The group assignment process maybe restricted to using real-time communications between server 260 andthe player via client system 214, or it may take place sometime aftergroup assignments have been downloaded to client system 214. Havingdescribed the player IDs and group IDs defined in the present invention,the use of these IDs in the targeting protocol is described next.

Library server 260 includes a player ID table 266 as shown in FIG. 2.Player ID table 266 includes a storage area for private IDs and publicIDs. The private IDs are pre-loaded into player table 266 when a newmobile playback device is installed into the system or when a new groupis established. In another embodiment, ID table 266 is a mathematicalfunction which converts group or player public IDs. Public player andgroup IDs are sent by a client computer system 214 to the server 260when the client computer system 214 desires to target a particularplayer 212/226 or set of mobile playback devices 212 to a particularspecified digital information, software content, or configuration dataselection. Digital information selection is made from the files 262stored on library server 260. Software or configuration data selectionis made from files stored on server 260 or from data generated uponrequest by server 260. Software content and configuration data isprepared and scrambled in a manner similar to the authoring process fordigital information content. Once an association is made by clientcomputer system 214 between a set of targeted public IDs and theassociated data to be transferred from server 260, library server 260creates a targeted header for the selected files. The library managementsoftware 261 consults the public ID to private ID table 266 to locatethe corresponding targeted private ID(s). The targeted header comprisesa combination of the descrambling map 322 from the selected files withthe private player IDs corresponding to the targeted mobile playbackdevices 212. The descrambling map 322 is thereby encrypted using thesecret IDs of the targeted mobile playback device(s) 212. This targetedheader is linked with the corresponding digital information or softwarecontent of the selected file in a network transport ready data block. Adigital signature is applied to the data block as described below inconnection with the data signature protocol. Transport integrity data(such as the use of checksums or cyclic redundancy check) is applied tothe data block and the data block is sent to the client computer system214 via network 240. Because the data block can only be unscrambledusing the corresponding descrambling block 322 in its header and becausethe descrambling block 322 was combined (i.e. encrypted) with a privateID known only by the targeted mobile playback device(s) 212, only thetargeted mobile playback device(s) 212 will be able to unscramble andread the data block. The selected digital information, software content,and configuration data is thereby targeted to a particular set of mobileplayback devices 212.

For small groups of mobile playback devices 212, each targeted header ofa digital information file may contain a plurality of descrambling maps,each associated with a different player 212/226. In this manner,multiple mobile playback devices 212 can read a single file 220 storedon the client computer system 214.

A person of ordinary skill in the art will note that alternative methodsof targeting exist. In an alternative embodiment, library server 260uses the targeted recipient's private player 212/226 identifier or thetargeted group's private group identifier to generate scrambling map316. Descrambling map 322 is not stored with the file as it is alreadyknown by the recipient player or group. This method targets content to asingle player 212/226 or group and achieves the identical result ofpreventing unauthorized playback of content.

In another alternative embodiment, library server 260 does not scramblethe digital information content or uses a known key to scramble thedigital information content. In this embodiment, descrambling map 322 isunnecessary and is not stored with the file. Either the public orprivate player 212/226 identifier can be stored in the header fortargeting identification purposes. Upon receipt of data from libraryserver 260, the player 212/226 checks if its player 212/226 identifieror group identifier is included in the header. This method assumesunmodified mobile playback devices 212 and achieves the identical resultof preventing unauthorized playback of content.

In another alternative embodiment, the player IDs for the targetedmobile playback devices 212 are sent to the library server 260 by theclient computer system 214 when the user registers with the libraryserver 260 to obtain the user's client ID. In this alternativeembodiment, these player IDs are stored on the library server 260 in auser profile. In this embodiment, the library server 260 manages theplayer IDs for the targeted mobile playback devices 212.

Digital Signature Protocol

The third authentication protocol used in the present invention is thedigital signature protocol. For selected data blocks generated bylibrary server 260 and downloaded to a client computer system 214,library server 260 uses its private library key 263 to apply a digitalsignature to the data block. The digital signature comprises a known bitstring or data pattern which is combined with the data in data blocksthat are downloaded from library server 260 to client computer system214. The library server 260 may perform this operation on all the datablocks or a selected subset of the data blocks. After a data block isdownloaded to a player 212/226 through a client computer system 214, theplayer 212/226 can retrieve the digital signature applied by the libraryserver 260 using a public server key known to the player 212/226. Theplayer 212/226 can thereby verify that the data block originated with anauthorized library server 260. The public server key is also known toclient computer system 214, which can perform the identical operation toverify that the data block originated with an authorized library server260. In this embodiment, library server 260 performs signatures on thecontent. A person of ordinary skill in the art would realize that thesignatures may also be performed on the digital information by authoringsystem 280. The signatures may also be performed in a multiple stepprocess shared by authoring system 280 and library server 260.

In an alternate embodiment, digital signatures are applied to downloadedmaterial by a trusted client computer system 214. In another alternateembodiment, digital signatures are not applied to downloaded materialand system security rests on the use of targeting and/or point-to-pointauthentication.

Downloading Digital Information Content, Software Updates orConfiguration Information From the Client Computer System to the MobilePlayback Device

In a first step, the client computer system 214 and the mobile deviceuse the point-to-point authentication protocol described above to verifythat an authorized mobile playback device 212 is communicating with anauthorized client computer system 214. If this is the case, the mobileplayback device 212 transmits its memory map to the client computersystem 214 via the mobile device interface 221. A table of contentsdefining the available digital information files 220 and playerconfiguration profiles resident in client computer system 214 isdisplayed along with the mobile playback device 212 memory map for auser of client computer system 214. The user selects which files 220 ofclient computer system 214 should replace portions or segments ofspecified mobile playback device 212 memory as defined by the mobileplayback device 212 memory map. Alternately, client browser 219 can beconfigured to automatically perform this selection process. In eithercase, the user is prevented from selecting digital information contentlarger than the available memory of playback device 212. In addition,control software and/or configuration data for playback device 212 maybe automatically updated by client computer 214. The specified digitalinformation files 220, associated headers, operating code, orconfiguration data are thereafter downloaded into mobile playback device212 memory. The mobile playback device 212 uses checksums to verify theintegrity of the download. The mobile playback device 212 uses theserver public key 215, the header, and the digital signature toauthenticate the download as described above. The header descramblingmap is used by targeted mobile playback devices 212 to unscramble thedownloaded data. In other embodiments, mobile playback device 212 mayunscramble the downloaded data and/or decompress the downloaded databefore authenticating the signature. Each segment of the digitalinformation content may be independently authenticated and validatedusing any of the techniques described above. Digital information promptson the mobile playback device 212 guide the user to the desired portionof the downloaded digital information content as specified by the tableof contents residing in the header of the downloaded data. The user maypreview selected portions of the digital information content byselecting a preview option. The preview option plays a predeterminedportion of a selected digital information program. Upon selection of aparticular digital information program, the selected digital informationprogram is played for the user after the mobile playback device 212converts the digital information content into sound or displayableimagery which is played through an audio output means or displayed on adisplay device.

The software player 226 of client computer system 214 may also receivedigital information content in approximately the same form as thedigital information content downloaded to the mobile playback device212; however, the digital information content for the software player226 does not need to be downloaded to the software player 226. Thesoftware player 226 has direct access to the digital informationcontent; because, it shares memory and/or disk storage space with theclient computer system 214. Therefore, there are no downloading ormemory map concerns. In the same manner as the mobile playback device212, the software player 226 performs digital signature verification,verification of checksums, and receiving targeted information. In analternative embodiment, software player 226 may use a communicationprotocol similar to that of mobile playback device 212 when receivingdigital information content, configuration information, and dynamicallydownloaded software.

FIG. 4 illustrates an alternative embodiment of the present invention.As shown in FIG. 4, authoring system 280 can support a plurality oflibrary servers 260. Each library server can be configured to support aspecific type of digital information content. In the same mannerdescribed above, the client computer systems 214 access network 240 andobtain digital information content from any of the library servers 260after performing the authentication process described above.Authorization server 270 is provided for this purpose. The configurationillustrated in FIG. 4 provides a more distributed architecture therebydispersing the load across several server platforms. A site with manyclient computer systems 214 may have its own library server 260 toreduce demand on network 240. This architecture scales well as thenumber of client computer systems 214 grows and the content provided bythe library server 260 grows.

FIG. 5 illustrates another embodiment of the present invention exceptthe library server 461 has been implemented as a plurality of separateprocesses or tasks 460 running concurrently on a single library serverplatform 461. Each library server process 460 services requests foraccess to its corresponding portion of the digital information content.This content is created using authoring system 280 in the mannerdescribed above. The authorization server 270 is used to validate thelinks between the client computer systems 214 and the library serverprocesses 460. The configuration illustrated in FIG. 5 is advantageousin that the convenience of a single server is maintained while thescalability of multiple libraries is also supported.

This concept can also be used for the authoring and authorizationservers 280 and 270, respectively. As shown in FIG. 6, the authoringsystem 280 and the authorization server 270 is implemented on a singleplatform 685 as authoring process 680 and authorization process 670.These processes perform the same functions as described above, exceptthe implementation provides the convenience of a single server and thescalability of multiple processes for the authoring and authorizationtasks.

FIG. 7 illustrates yet another alternative embodiment wherein the clientcomputer systems 214 include a local library 710. The local library 710provides a local storage area and library access control functionalitywhich provides access to a subset of the archived digital informationfrom library server 260. In the manner described above, the user of aclient computer system 214 identifies the titles or items of digitalinformation in library server 260 that the user wishes to access. In thepreferred embodiment, these content selections are transferred to aclient storage area 220 (as shown in FIG. 2) for subsequent downloadingto mobile playback device 212. The embodiment shown in FIG. 7 expandsupon the client storage area 220 and creates a local library 710. Thelocal library 710 is used for storage of selected content; but also forsearching, sorting, categorizing, and abstracting the locally storedcontent. The local library 710 allows a client computer system 214 tomaintain a small subset of the full library which may be used to createcustom collections of content in a variety of user selectedconfigurations. Client systems 214 may be permitted to access thecontents of local libraries 710 on other client systems 214. In arelated alternate embodiment, library server processes 460 may alsoreside on selected client systems 214. This embodiment allows clientsystems 214 to browse and purchase content that is scrambled, targeted,and delivered from library server process 460 executing on a locallypositioned client system 214. By maintaining the library locally, aportion of the network access and transfer overhead is eliminated.

FIG. 8 illustrates another alternative embodiment of the presentinvention wherein the client computer system 214 is eliminated and themobile playback device 212 is connected directly to the network 240through network interface 810. In the preferred embodiment, the mobileplayback device 212 is a minimal capability device primarily dedicatedto playing audio files or displaying visual images or text on a displaydevice. The mobile playback device 212 is minimally configured to retainits light-weight, low cost, and readily mobile features. The preferredembodiment does not therefore include the use of a portable personalcomputer or laptop computer; because, such devices typically do not meetthe light-weight and low cost constraints of the preferred mobileplayback device 212. However, the minimal mobile playback device 212 maybe augmented to add network interface 810 which comprises a conventionalhardware connector, hardware buffers and controllers, and firmwaresupport for a particular conventional network protocol. For example, themobile playback device 212 may be augmented with an integrated modemthat includes a telephone jack with which the playback device may beconnected to a telephone network. It will be apparent to those ofordinary skill in the art that network interface 810 may be implementedin a low cost and light-weight device such as mobile playback device212. Because the client system browser 219 would not be available in thealternative embodiment shown in FIG. 8, a simplified user interface maybe provided in firmware or other non-volatile memory of mobile playbackdevice 212 with which the user may select items of digital informationfor download and playback from library server 260. As described above,the authentication process to validate the link between the mobileplayback device 212 and the library server 260 must also be performedprior to user access to the library server 260 content. Alternatively, aclient system 814 coupled to network 240 may be provided to supportclient browser 219 and thereby enable selection of items of digitalinformation for download and playback from library server 260 directlyto any of the mobile playback devices 212. Client systems 814 maysupport local storage of digital information, software, andconfiguration data in a form similar to storage space 220 or locallibrary 710. In addition, a more simplified implementation of networkinterface 810 may be designed to communicate via network 240 to clientsystem 814 instead of library server 260.

In another alternative embodiment of the present invention, digitalinformation programming selections are made using the client computersystem 214 and library server 260 as described above; however, theselections are delivered on mass storage medium 241. Mass storage medium241 represents any of a variety of conventional mass storagetechnologies including CD-ROM, PCMCIA cards, DVDs, floppy disks,removable hard drives, digital magnetic tape, optical cards, flashmemory or other optical, magnetic, electronic, or semiconductor memorydevices. Upon selection by a user of a client computer system 214,selected programming is targeted and scrambled as described above andtransferred to a selected mass storage medium 241 and mailed,hand-delivered, or held for pickup by the user. Once the user takesphysical possession of the selected mass storage media 241, the selectedprogramming may be read from the mass storage medium 241 by the clientbrowser 219 and thereafter transferred to the mobile playback device 212as described above. FIG. 9 illustrates another embodiment of the systemthat does not include the use of client computer 214 to transfer data tomobile playback device 212. Kiosk 910 consists of a computer system suchas the one described above in FIG. 1. Kiosk 910 is a publicly accessibleunit that can perform browse, content purchase, and download functionsin a manner equivalent to a client computer system 214. The kiosk 910 isspecial because it contains its own library server for fast local accessand download of content. Kiosk 910 contains a mobile device interface221, a special version of client browser 219, and local library serverprocess 460. Kiosk library server process 460 has local storage ofscrambled and compressed digital information files 262. These compressedinformation files 262 originate from remote authoring system 280 and maybe delivered via physical transport of mass storage media 241 or viadistribution network 240. A customer operates client browser 219 tobrowse, select, and purchase digital information files that aredelivered to the customer's mobile playback device 212. Authentication,targeting, and download processes are performed within the kiosk bylibrary server process 460 that is connected to remote authorizationserver 270 over network 240. In a related embodiment, FIG. 7 shows aclient system 214 with local library 710 that can be converted into akiosk with functionality similar to kiosk 910. In this system, a specialversion of client browser 219 provides the same user functionality asthe previous kiosk embodiment.

An alternate embodiment of the system uses a common communicationnetwork to connect all system components. In FIG. 10, network 240 isdirectly coupled to client system 214 and 814, network interface(s) 810,library server(s) 260, authorization server 270, and authoring system(s)280. One of ordinary skill in the art will realize that network 240 canalso be segmented into a number of independent networks or communicationlinks without changing the functionality of the system.

Thus, a method and apparatus for implementing a computer network baseddigital information library system employing authentication andencryption protocols for the secure transfer of digital informationlibrary programs, software, and configuration data to a client computersystem and a mobile digital information playback device removablyconnectable to the client computer system is disclosed. Although thepresent invention has been described with respect to specific examplesand subsystems, it will be apparent to those of ordinary skill in theart that the invention is not limited to these specific examples orsubsystems but extends to other embodiments as well. The presentinvention includes all of these other embodiments as specified in theclaims that follow.

1. A computer based library and information delivery system forgenerating and maintaining a plurality of digital information files fordelivery over a public network, said library and information deliverysystem comprising: an authoring system including programming logic forreceiving raw digitized data, logic for transforming said raw digitizeddata into said plurality of digital information files, and logic forgenerating information indicative of various characteristics of contentof said digital information files; and a library server comprisingcomputer hardware, wherein computer hardware in the library server iscoupled to said authoring system which includes logic for maintainingsaid plurality of digital information files, logic for maintaining acorrespondence between said plurality of digital information files andinformation indicative of a player ID, and logic for encrypting saidplurality of digital information files using information indicative of aplayer ID, said digital information files including said informationindicative of various characteristics of content of said digitalinformation files and authorized for access by a user on a mobile devicebased on a corresponding player ID.
 2. The computer based library andinformation delivery system as claimed in claim 1 wherein said pluralityof digital information files includes audio files, spoken audio files,visual image files, text files, video files, multimedia files,programming code files, configuration information files, or anycombination thereof.
 3. The computer based library and informationdelivery system as claimed in claim 1 wherein logic for transformingsaid raw digitized data into said plurality of digital information filesfurther include logic for compressing, scrambling, and segmenting saiddigital information files.
 4. The computer based library and informationdelivery system as claimed in claim 3 wherein said logic for scramblingsaid digital information files further includes logic for generating adescrambling map for descrambling said scrambled digital informationfiles.
 5. The computer based library and information delivery system asclaimed in claim 1 wherein said logic for maintaining said plurality ofdigital information files further includes logic for incorporating saidinformation indicative of various characteristics of content of saiddigital information files and portions of content of said digitalinformation files into said digital information files.
 6. The computerbased library and information delivery system as claimed in claim 1wherein said logic for maintaining said plurality of digital informationfiles further includes logic for receiving requests for access to saiddigital information files and portions of content of said digitalinformation files and logic for authorizing access to and managingdelivery of said digital information files and portions of content ofsaid digital information files in response to said requests for access.7. The computer based library and information delivery system as claimedin claim 1 wherein logic for maintaining said plurality of digitalinformation files further includes logic for collecting and storingusage statistics based on access history of said digital informationfiles.
 8. The computer based library and information delivery system asclaimed in claim 1 further including an authorization server coupled tosaid library server for authorizing access to said plurality of digitalinformation files.
 9. The computer based library and informationdelivery system as claimed in claim 8 wherein said library server andsaid authorization server run on different computer systems.
 10. Thecomputer based library and information delivery system as claimed inclaim 1 wherein said library server is a software process running onseveral computer systems.
 11. The computer based library and informationdelivery system as claimed in claim 1 wherein said library server andsaid authoring system run on different computer systems.
 12. Thecomputer based library and information delivery system as claimed inclaim 1 wherein said digital information files are targeted using aplayer group ID.
 13. The computer based library and information deliverysystem as claimed in claim 1 further including authentication logic forauthenticating access to said library server, said authentication logicincluding logic for performing a point-to-point authentication protocol.14. The computer based library and information delivery system asclaimed in claim 1 further including said authentication logic forauthenticating access to said library server, said authentication logicincluding logic for performing a digital signature authenticationprotocol.
 15. The computer based library and information delivery systemas claimed in claim 1 wherein said digital information files includesfiles with primarily textual content.
 16. A computer based library andinformation delivery system for maintaining a plurality of digitalinformation files for delivery over a public network, said library andinformation delivery system comprising: a library server coupled to anetwork, said library server comprising computer hardware, whereincomputer hardware in the library server includes logic configured formaintaining a plurality of digital information files, logic formaintaining a correspondence between said plurality of digitalinformation files and information indicative of a player ID, saidplurality of digital information files being encrypted using theinformation indicative of a player ID, and logic for maintaininginformation indicative of various characteristics of content of saiddigital information files, said digital information files beingauthorized for access by a user on a mobile device based on acorresponding player ID.
 17. A computer based library and informationdelivery system for maintaining a plurality of digital information filesfor delivery over a public network, said library and informationdelivery system comprising: a library server coupled to a network, saidlibrary server including logic for maintaining a plurality of digitalinformation files, logic for encrypting said plurality of digitalinformation files using information indicative of a player ID, and logicfor maintaining information indicative of various characteristics ofcontent of said digital information files; said digital informationfiles being authorized for access by a user on a mobile device based ona corresponding player ID; and a CDROM generating device for generatinga CDROM having at least one of the plurality of digital informationfiles and at least a portion of said information indicative of variouscharacteristics of content of said digital information files.